1. Field of the Invention
This invention relates to an improved process and catalyst for the production of hydrogen-rich gas.
2. Description of the Prior Art
The catalytic water-gas shift conversion process may be used in the manufacture of hydrogen containing gas mixtures.
The water-gas shift reaction is represented stoichiometrically as follows: EQU CO+H.sub.2 O=CO.sub.2 +H.sub.2
About 16,700 BTU's are liberated for each pound mole of CO converted. Heat removal and temperature control are therefore necessary to prevent destruction of the catalyst and to attain the desired CO conversion. Ordinarily, the reaction temperature is held in the range of 350.degree. to 1,050.degree. F. (depending upon the catalyst used) by employing two or three separate fixed beds of catalyst. The shifted gases from one bed may be passed through an external heat exchanger and cooled from a high temperature to a comparatively low temperature before being introduced into the next bed.
A typical conventional water-gas shift catalyst is iron oxide promoted by chromium oxide. This catalyst is referred to commonly as a high temperature shift catalyst because it has an ignition temperature in the range of about 600.degree. to 710.degree. F. The effluent gas stream leaving a reaction zone containing high temperature shift catalyst is at a temperature in the range of about 715.degree. to 1,000.degree. F.
Coassigned U.S. Pat. No. 4,021,366 pertains to a process for the production of hydrogen-rich gas by passing a feed gas stream sequentially through a catalyst comprising cobalt-molybdenum or one comprising 3 parts by weight zinc and 1 part by weight copper, and then through promoted iron oxide catalyst.
In U.S. Pat. No. 4,032,556, the methane content of a gas produced by the hydrogenation of a liquid hydrocarbon with a hydrogenating gas at high temperatures is increased by contacting the gas stream with a supported nickel-urania hydrogenation catalyst comprising a maximum of 10 wt. % uranium. U.S. Pat. No. 3,993,459 pertains to a catalyst for converting higher hydrocarbons into gas mixtures containing carbon monoxide, methane and/or hydrogen in which the active components are oxides of the metals lanthanum, cobalt, nickel, uranium, cerium and thorium on an oxide substrate. The catalyst comprises from about 0.1 to 8 percent by weight of uranium. In U.S. Pat. No. 3,847,836 liquid hydrocarbons, e.g. naphtha are steam reformed using a catalyst comprising nickel, and/or nickel oxide, together with a relatively smaller amount of uranium oxide supported on a carrier.